Many greenhouse and nursery operations process hundreds, if not thousands, of individual plant seedlings. As a result, an equal number of individual pots or containers must likewise be handled. Economies of scale can only be utilized if such operations become mechanized or automated. As described in U.S. Pat. Nos. 4,684,013, 4,962,855, and 5,022,183, loading trays have been developed with cavities shaped in general conformance with the shape of a pot and spaced in such a manner as to fit over multiple inverted pots simultaneously. While growing trays of this sort alleviate initial handling concerns, they do not promote and advance the state of plant care and nurture.
The search for an effective, integrated system for commercial plant cultivation has been an ongoing concern in the art. One approach, which has been used with certain success involves use of an open tray with cavities for individual pots in conjunction with a centrally-disposed watering tube, as described in U.S. Pat. Nos. 4,887,388 and 3,613,309, respectively. Such systems of the prior art rely on an array of stand-offs on each pot to raise the plant container above the induced water level and ensure circulation of fluid and air among the plants. Excess water flows out of the tray through openings in the upper portion of the tray wall.
However, the prior art has associated with it a number of significant problems and deficiencies. Most are related to restricted utility, and result from the type and configuration of the growing trays currently used.
One major problem is that current bench systems are immovable and growing trays of the prior art are not designed or constructed to be movable while in use. If moving many weighted containers is necessary, each must be handled individually, rather than together while in the tray. As a consequence, watering and related care must be interrupted or discontinued. If placed upon a pallet or a similar support system, such trays may be moved only with the risk of sliding off the pallet or loss of contents.
A related problem stems from the fact that certain plant varieties may require periodic shade or refrigerated temperatures at certain points in their growth cycle or under certain weather conditions. Even if growing trays of the prior art permitted the containers to be moved collectively, prolonged exposure to cooler temperatures would cause the trays to crack or otherwise be damaged under the stress and weight conditions.
Another serious problem is caused by the fact that growing trays are often subjected to long periods of intense sunlight, in particular, the ultra-violet or "UV" component thereof. As a result and at an extra cost, a UV-inhibitor is often incorporated into the material from which the trays are constructed. Even when an additive of this sort is included therein, the functional life of a tray is short and lengthened only marginally.
The materials of the prior art tend to develop and hold a static electrical surface charge. This is extremely undesirable characteristic in that such a charge attracts and holds dirt and/or vegetative material which, in turn, promotes the growth of bacteria, algae, and fungi harmful to plant life.
In summary, a considerable number of drawbacks and problems exist in the art relating to growing trays. There is a need for a growing tray which will accommodate a variety of horticultural demands and enable growers to better utilize the available technology.